Phase stability and hot corrosion behavior of ZrO2–Ta2O5 compound in Na2SO4–V2O5 mixtures at elevated temperatures

For thermal barrier coating (TBC) applications, yttria stabilized zirconia (YSZ) is susceptible to hot corrosion. This paper examines the hot corrosion performance of ZrO2/Ta2O5 compounds. Different compositions of ZrO2–Ta2O5 samples in the presence of molten mixture of Na2SO4+V2O5 at 1100°C were tested. The compositions were selected to form tetragonal and orthorhombic phases of zirconium-tantalum oxides. Results show that orthorhombic zirconium-tantalum oxide is more stable, both thermally and chemically in Na2SO4+V2O5 media at 1100°C, and shows a better hot corrosion resistance than the tetragonal phase.